You can start by not making the color of a crystal rare, but instead by making the stats of it rare, and introducing more craftable colors. If you want rare crystals to have rare colors, then use different shades.

Also free up Purple, and Teal (LTBLUE) for use by both sides.

Dear Bioware, my Birthday is in March > I'd like to see Purple, Gold, and Teal crystals obtainable by all players and the four major play styles by then. The four major play styles are CRAFTING, SOLO, RAID, and PVP.